SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa16ba0bfa22d3774ddc29df7a655239f868851671cfc2b27816c3b3b4dc7fd5' 
  AND token = 'sJIfHPA503WDb0ZYeVnBvuDwrVFqT6gQ2LQBBEPJAoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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