SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9210c7d457f9910f5cb1a91d7dacaed35acc44f7b7a30f5698f1267eea357f4b' 
  AND token = 'WQOTfkRpEebRfoqZdK9nG4zunlPIHa3Ma02xsOuBAnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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