SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7caf0efab7938bba45956abc6376ed4db3b9beb31c7be07fe60dc96f0be26993' 
  AND token = 'WIiMiJVtDP4NE2X9FM+Zs7jLPIZPASCb3QOT2Yf2dZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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