SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce89716a1e4ee924741597e78dcba251d5d60732c4f0362f4730f4d30fc0d2d3' 
  AND token = 'A2lL8PMe6mQGkloJn12pOJYCjFvSZojkOsZEhLel9tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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