SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4470a88ada99094f4667aa2e3266381623b40bfcc99bfbca5b646517918556e4' 
  AND token = '5b7UrZ9GrkufuNuLHd1ioMfbpx3wiLR86VUIU1fOxeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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