SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e32b529d706b631c978e5d33b08114672e457f75c0eaa5053ac69867d8a6473' 
  AND token = 'yZK5RXjvfDOHJv0os+QdKUOjUowI98pfjf6exu6Hfpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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