SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db07a1ff5f4f28cb0892469603561a64fc04f8dfb6ee5844460f046a25e65900' 
  AND token = 'DwonbEDWF362GbJ6/ijQeH9J2sxJZfPLTTqzlS2Ob+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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