SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25ce7c2b77752d96c4cd45b15f8e1e694a3c7da41d4f97f8f055df26b60536d6' 
  AND token = 'j6C6awFhLsG4DVjxkWJW2gZvq+stZ67XHKqxfnqEg9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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