SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5989b0e0385e1d37ab95e5f96e6832ec203717270ff01d0ee3dcf87f14c7811' 
  AND token = 'bajdDl3CkOVLJNf6KwF7RxcEDTcc7gBoRkuKYTn5shk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}