SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114851974c713fe1de15b8bdb2fdf2c294ffd36f08a22875459ba9672ffba18c' 
  AND token = 'zmPrwFyJmIdO27+4q4Y7/lI1cgr7QgI/MYyY7CLhWs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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