SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ced7b7522748119a6a3674b90ad57be315aa821c283a212ff58bea85524a74c8' 
  AND token = 'HKiraxuDMEhO0BYYdNSfSl8CSlOdYqajg6JbwIvurNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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