SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a69fe1bdb809f98b4a2b233f14e9fdb2e3a24e4dae52cb6a66242d4a12612281' 
  AND token = 'geKoawjxPSLHJ8j4gynnfrK5cdlygJbIe6JIgP0nBhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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