SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c41b754c62986e058f60dde34cee4e084f6c4e9a9e8c9bb9e47ddbecf114f96' 
  AND token = 'B2ITr56dUrTlT1KOrDw4MmDy2FKusubAwEzzg/1NGec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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