SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f417b04b030e2a6dcafc48bc9050041d9bd228cfd2bab5929ca3e0cf8edeefd' 
  AND token = 'tW//wStxgCpxH2O1vHgYJUziy17CLyU55ssJFJet2SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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