SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30a44f60b04a652ae02ff0a7598964aaedd985f45cb79173327a7673df1b4f8' 
  AND token = 'tHFDMLPA1xmZ1TQdhYYaXHXRrpH3CVGjtYo942rm3jM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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