SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '778b334fe01ba6c196c0ecc1344e6dad06994f33e6da5a6048ad3b5b58228823' 
  AND token = 'n8ve5+ehg4YzYr8QzSTbVX/5+LFyONBgCC5MQ4EDvP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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