SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c9aa44440a015799bf36588f9bd2235fd61a297867046140c7d5c382cc8099f8' 
  AND token = 'mXU0BTWtmV5pQG04sFNra4QZjJvdiljjImqSJOy1oeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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