SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15970511040933649b79163cc65cede082f9164e8e8ce6e0cab8ea347fd50d01' 
  AND token = '1eZfqTbcFMXPeI28PMEc6BS/d2Sd1GqpbObWY0cRjrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}