SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '582716bcc180e11085e80f13eeb104c0066c5922709d549add1c975af5fdffa4' 
  AND token = 'nrQjvqvpCHn0thsTRwzUnwbnJL8GqByEpbpfcshdA+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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