SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '808a0f82feff7468814c13c2c091e4701a90c45c797a630ef85a230f31573c14' 
  AND token = 'N/DucStudqulI6qZY3nMPtn3OJbHGC5prQcSYpnEQPk=' 
  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"
    }
  }
}