SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c65cc60e06d8268554a34de63dc5d424a21bc274919ed2b3dcd0569645da61c' 
  AND token = 'ntHwn0gU7VnWldjAjlmQ72AWc3iRGi1JXVSovLhil64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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