SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ff5b6c3e4f62d14226b4b2c14bd0b0e2f270995a8902e46eb553661e1625f0' 
  AND token = '/d38K2wZvqOyYQj0evxPLVuYeZ04G7eq7KnQHOD+ZLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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