SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b46cad625db0f3577e663709a26d712e301b6cb034a155aa0f2080a0608153c9' 
  AND token = 'CPiRl2k10OJbOXpQAYCajHBDNNoBwCT0LUmlfRFyjSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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