SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e1674d830015240b9b1e4f44276843bb73174b772a8337120cf9c2a15702f3a' 
  AND token = 'aVx5s+iGaO3C/zlYgZ3K3PjG33p8SYhZG4GkQ6FlPYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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