SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92181b54cb1602781dd39c7e57dc90945240fa4b332db7c896c92fd16ae43740' 
  AND token = 'M/5U7NdV7hCNV6tubtSabqM0yrnZXDaVaFpLaR4f00E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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