SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49e44064b2c09e81783193ebab6f9fee5e936b4059f4ef9edf8c4b223bfeeba6' 
  AND token = 'OsfIM08xV3AYAuhRdVESUg3cvak48LaHnjRV95dqrUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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