SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd8e2df76847ef763392dbe600b2678da13c0bcafa16153a8bcc8896075057520' 
  AND token = 'aY7nD59Du3nnPXDOCGIQPKPwtVDZyeRAkZiQIbeCats=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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