SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2863febc0826d2d828ffdb7f28424586a7e67b94a0dd87490eca5ba208974516' 
  AND token = 'iZ0dT1sujxjgxpcY0ol6jxl6Dz4fWdMFO4+R2pGvLRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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