SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45c0fae17289e57c7dd471bee121d7883fd431e9ecdf22fa6175a347e6758f6b' 
  AND token = 'wFBwVjf902jyhiv9kKYdAwDAat51T1hX2S6stj22iHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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