SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2027e3336c13c1135e67b5af0afc01e006572f5e5964c8d47c532c89c47c046a' 
  AND token = 'fYS50wGluNQBlsfuEHJqVDuYaO+5sLhTUEue5XCKZSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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