SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92cc60829afa20b0daa68b67449fd6d465a9c74ec61f4a0abe69b6a93e2e8475' 
  AND token = 'Df/DfK+knbVQmJjL75aHASC8fl07JlcELQh5gYEyCmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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