SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af3982e92f0359faa2f07b1f91b24f4cc4240cda3c7a78b4ffc4f59e24291174' 
  AND token = 'AfDKOFZ6y4kO7q3c/K4Ix4dIW/Cc/PUFnw2roRYPURY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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