SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57db6a98b73f7c5e3fc1d229b1121318934008fcedc2f42bbff4673c0fb917b' 
  AND token = 'ZChKxKoil5GuK7vT4o2nZrQKoyBRz91gwnUnQ5GvAUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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