SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d560816f97f3fe3e8b36f63eb3e91c22cc257e8718e30733e7cc1f9f2a1d90b' 
  AND token = 'Jqujs5WCA+41U4V0U2p43t2RwLLznGQ6qIyOv6Las5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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