SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '460f2a69708e75e05a972c7aa460e543f61cca791ee2146891d37a96de84fcd1' 
  AND token = 'BAIWdpxs4aHhSOwA89ZRG/R5giqBfv+be1PPjuLoWzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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