SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1409da52fb48f97e2e6be9c1eaf788da1e805476b18ba986179006379cc1d662' 
  AND token = 'tFJ83I7a5ZosArggEgNiC2x79A3ibfH+5i03i4olZ38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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