SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa0a5b7f669e4240528298035fc41179d287e208ec62a4921c831db5515e73ef' 
  AND token = 'BzsrVH+ffMOmlZVPOeS5/JyZbkLWYakZM0PGJjBNs7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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