SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a348e30b443cce0ea1ae5422af0b3788c6654ab93a8ba68dfe8d708e1307e8dc' 
  AND token = 'XXvlhWXNdG5QKVkLJLYzedP+kFeV0h+Ls8OCYIUnb94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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