SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '515b5e59041f6dd464aa93b3f92f0251a5bf00691bbda01c8456770114453f6e' 
  AND token = 'MoMdyv46SOThjfRnC3RQseFUxvEJwAi0txTh4exltnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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