SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc2ce300b14ff35c2cabc8649fbd4370ce35b093ab829aef822eb3006e8481ee' 
  AND token = 'TiJOk0BfS1nJvDYWIpmDmp/nhPXYEQtLpkrRY4NTLro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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