SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa818aa90e34c805bfe09d7c279b9d33e5195dbd0c5b2599290eeb89eaefae47' 
  AND token = 'mIOrnM67O88geuGXAf6xcUyCZ+sMEzT1vPwnnOi/mPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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