SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efd022c01bef9f7ff8291659fd5478249ec31d53a163e84d9124e16a84453a3c' 
  AND token = 'rkzaTAfGSfkFrPC610D5O5rVH8Ug/ZmU4qXmMnIj4zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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