SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb2223d0deaf92abd539927400cba6c04e4ecc539120cae088fe28e48a65bc6' 
  AND token = 'YaGPYXZg3YDDpP7tVPuQPn/wP6PCBnaDzCUi0sSxgbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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