SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7fdafa949404db21c96edf37b6aa919370272193d71fe50ba0e7729ff9eb440' 
  AND token = 'RroNaOzqcuZuq7j5Ik5Rczw4dFND66h2bElnOHaBiOY=' 
  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"
    }
  }
}