SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6368b2217dcc347ace4b53b5b0080561897d530017f992b9fad4b90faa5fdba' 
  AND token = 'DC/Bm8I7XFl09/j1LGUcBMZ6/Luuo0tpI0oRUJXMUU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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