SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65313006f566858052491ecea0c1190f117853768663227240a676c05d1ff058' 
  AND token = '7MIiuEH2KgPhg3qYZFj5WvlRmyYFIEgfjytw6wrCxec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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