SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d36bdfac28ea128cb6534d174e80fed48128f8cf63b264a57a46a3d9b1e11cc' 
  AND token = 'EhYNPfgKis3PuDTErrv7eNofbEbnkaCZVu878/UBj7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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