SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84c417562b384496a7d827ff1b209ffc84f190c99fea7854a80446de8d557dfa' 
  AND token = 'afEW1ie7ChbJWPG86AUYLiJXIOrg7hR8x3MyzHg81I4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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