SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c7b013b0f93b183ff3fc57ed92e04bc95c5c57f846ca1980fcb4be2899b204a4' 
  AND token = 'JGhYz2hQflG+PdZyh2DlwKdgLjbCHVjoZ3DAivRaiUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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