SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dc8565f887753c2f88ff356641e5ab5e9cd52ffa2cc215f1fb13aa5f616a8a7' 
  AND token = 'zqrf0+WnYgtL248agydhNpKPaXORenlP/U3Fx36UJ/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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