SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abde5426b1beefd60e8e9c71643338365cb6c7c6f3b20af8befb5d4f34825845' 
  AND token = 'h3F84fSmcCYW1aCdG8bm12n80DOcjkmr1wx9QBR71xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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