SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '174b3cee4f632917849b78fcf7ee09dfaa1e66be99dad9b75b9826cb9b66ef57' 
  AND token = 'vZc3kx1WtFLZKDs+xp/gXIUCsVJ/Cj9z/XFHA2G1e0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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