SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98a440c14ffb868762bb9f0b017df55200297226a23329d95d2523ea9e57c6f' 
  AND token = 'mgQ8MrQOU3BdeESohWssbmE7WnAEXFQsfPfsKqpw+yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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