SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cca315d78026cd9931a6ee2d469f94c98f6be916dda6f35dfabeb7eea4cfc270' 
  AND token = 'hVMI+N3OWDgNDnggSze3Wf9Ye9MM3hGGo7vPuqIheS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}