SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd50693e9df18d4755afbadadfb1f60f006f63421f5da612633bd72d80812c024' 
  AND token = 'ZxXvP3RoQ20eaKGezF2ZjOdyZqg3JgZF0JJw5kSRtXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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