SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '003eaec8247c1b37714b419d7b0b4f48e5da3203d8fd6e5d81beea712e3616f8' 
  AND token = 'G+f55RQyFNJxOcZVilEr0k2Kl75XXV82Wfk3flDikmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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