SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30692e230cc8cf1894c5bba0db1b81dd9d08ba4c89b30460ef179bd61f280975' 
  AND token = '2lU3NYofMUzaHXc66WJO/kk1WbjerSyLiOhBLeEqpIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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