SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b9083eae5809788ccd64876150749e0b5759479cc297deab53445ddadbc036' 
  AND token = 'YsJWxnwwcJwsVgSpIRtNHo6RBjidNnQgQD5ZRdZOo6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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