SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '337798cf808313c5b51d10fb29890854c9d67ab4df2fde2718fbdb71a9e5f12b' 
  AND token = 'hbXa7xLF0p6ysQpUThcK/tUhQXSpfzGffpFZVw1GCcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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