SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db9507eee9f0322c4e21f5b910eddd2437f74df7aab32169ef84549d4b4e5e74' 
  AND token = '0qUJAdq8ChpoUgNn+/UGBlXM+KDoMxsrJwRRcuD/g98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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