SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c3dd02e09e45af447c05b4038ed50df292c473c9b8b1a16d691f0e28382ab79' 
  AND token = 'HojYM6IUu0JH1VHOFGA0zpIxZR9Solmvt3zW1+yr6PY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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