SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42156c5fe3ebebffffa720e3967cb784a795df1705a5eebd2af37c68089833ec' 
  AND token = 'y59ENSuy2fVMpyeDukUzmBPlVESaFs7iMYh5xoIQ+8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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