SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af4c72fc1850f68eebee08dc30b5897cf91f97c4c449f82633fdeacc4c879c8' 
  AND token = 'zaExsWwp1VDsdsLU1E/n4Ow0+by4pWe/lbFSRsGwdYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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