SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77eabb2478071a6ff805aa79f51ca13fbbea7c7bbfa4fdcbfdfea8bc4f8e95a8' 
  AND token = 'xWDB41DmCW6TCbXqKToq3MNYurPE39jFQezv+g1pqBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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