SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a907a2f21e9e695e86b139b8e230b53b4ef8156c2122adb63311512aff6ed7' 
  AND token = 'pBfE0SjO1NECU4YhMDRWzQBn8e3XX2pJDLl38vgJvyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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