SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bbd0d9f9a68799e8b1c13c55d39296529b32d4fbbbaeb6364fae43452395d6f' 
  AND token = 'LoHRcFPgLmn8rlM7luUykpU6cFjv5rCaYpOZthQAr1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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