SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '334d107e63b833b79de220206f4f5d7fd98e6c9c64b0874b0dd42566bc8afded' 
  AND token = 'NA2E1GxKXyqNjFxy+VjIhwq3M1CwLUkmoUFveYE9v+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}