SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b6588323fb6d5cb0a1b29c373b8fc36d561685d806e73d69465facd6af9093c' 
  AND token = 'mFQ72mhjZ+MMdRyQgs9JRE4GaNoZtUPBqSX9Uf1v+SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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