SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbdb59b7413c1e6d39906f47f75259870c7195876a6e5d2d30f42830b0b0ebc6' 
  AND token = 'YNUhqHR4R4kNUOiVtXJhkUjCjHksXqwydn8ZIES/Xkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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