SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52d9bbbafd7b3355ee5127a247748fb133f525456b58494556fe9bc3ad172557' 
  AND token = 'ZKn2/ArSnOvlsCcXuGd6RGgDHSwCHAXWVFh8zNY1zc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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