SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2855ffe9cf369e29bb00155bb5e7b1be9fa24ea1ab52a4533b26d327f253d0f6' 
  AND token = 'D8d8GP0wgU5oYKFkP4rvU8JuJVp3p34OwNz9qTYKDfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}