SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '376be1b8cb4dcf597c00a45a028aa322775103cd202fbfd9723420c5f3ef3f65' 
  AND token = 'fcOeHqPVDwn5yuPmksNvYKkVY+L25CVhW805WWW7kUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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