SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b72a89f598f8df5bef3eadd484320713c26a516b0e57c4a281cfe93ba910890e' 
  AND token = 'Zm2yzUBzGiqgnuNz6ZuOFGeqF/lBRnQWe/i0tJgNT3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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