SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '312240df7ca06d7365529fed9bd36a8ba796cc358f4413891406eb0e49307d5a' 
  AND token = 'Pl4uQIgeO+hYGuQmWbl4q7MelOIq4lGmMWNW/ZsUxDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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