SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '485e377fab1520a859fa54c10f221e31994fe953925d63ba7d7c1f91047877a9' 
  AND token = 'QTY6jKCdySmq+wynWFphRPehTkoIeobr0IE3H1E4jMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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