SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a1fb3fb0ede52e6faacad6f74109091ae2c576f59e36e3babb2d5004875aac' 
  AND token = 's52XLx01mDDSfeuTH1N4+Tl0LrxEFicfqYwjjw1pmqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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