SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0abdd5274e02bb89d41fd60ff6abf8f39baf25cc82c14862778397c5af8e104b' 
  AND token = 'jHGRyE46LQVmQAQH4uwRDfaJrbAh9TuT/74YEz9bo+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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