SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7343a05569b818caad8eff862b4e4b5e57f018105db374996511d3c4c4603f' 
  AND token = 'AUVhzix54Up+HkrHX05plNrKzLxe0734N6SqmeJoMNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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