SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0da9492632f00cf787fab912296c05d75f85df32189bde2bd2a3eb11ecb46c85' 
  AND token = '387pHP7tBjx5z82o4erivkY5Rv6TvSXqelbfFFN+isE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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