SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4820c9e36b116ab70dbffa933f0ae4ec12c3db8c50e54719625c1978064dee' 
  AND token = 'm+lUmZCy5wmigZNhkzTg3V1rm7xLnz5UC572CVHusHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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